The Jam Session is a music-themed party for all land animals and was first introduced on April 25, 2013. It appeared in the party list very infrequently and was usually found once a week, but in 2021, it began to appear again much more frequently.
The party takes place on an outdoor stage during sunset with giant speakers playing music in the background. There are various instruments on the stage such as DJ Turntables, Keyboard, AJ Drum Set, AJ Guitar, and Bass Guitar. The stage has a backdrop with colored sheets and white Strobe Lights at the top. Jammers first arrive in front of the stage on a lawn that includes white lights pointing up at the stage.
Jammers can buy various music-themed items at this party's three shops: a clothing shop to the right of the stage, a den item shop to the left of the stage, and a music shop on the left side of the stage. Jammers can also dance on the stage to cause the strobe lights to change colors. Once five Jammers start dancing onstage, the lights in the front of the stage will shoot out flames and the music will change to include the main melody. Jammers can click on each of the instruments onstage to produce a different sound and make their own rhythms with these instruments to go along with the main music.
The music played at the party is a simplified version of Jam Session without the main melody. It only includes the background music consisting of bass guitar, drums, and electric keyboard. This music changes to the full version of Jam Session, including the melody, once many Jammers are dancing.
- This is the only party with music that changes depending on what the Jammers are doing.
- It is one of the four parties without the word "party" in the name, the others being the Jamaaliday Jam, the Best Guess Game, and the Call of the Alphas.
- This party appeared on the Parties list once every hour during the celebration of Make Music Day (June 21). During the 2016 celebration, this also included the release of the Rare Guitar Rug for one day only.
- The Welcome Party is based on this party and uses the same background.